Spot The Mistakes In This Manufacturer Marketing Video

John Honovich

This just released 33 second video showcases a number of mistakes and misleading assumptions. Test your video surveillance skills and see if you can find them. [Bonus: Here's a 1 question quiz to test yourself - also our improved quiz builder.]

Here's the clip:

And here's Raytec's description of what they did:

"Ghosting Demo with and without using additional Infra-Red illumination. The camera model used for the demo was a Panasonic NV-NP502 in 1.3MP Mode. The illuminator used was a VARIO i4-1 set at 20% power"

So what's wrong with this video? I see 3 immediate issues but before I give it away, let's discuss it.

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Chris Dearing

Ok, I'll make an ass (again) out of myself by saying we all saw that the ghosting was caused by the slow-shutter but assumed that it was necessary because of the low light situation. Are you saying the gain should have been cranked up first?

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Chris Dearing

Sounds like the camera might have been chosen purposely to make their point. But some people do already have existing installs with similar cameras, so do you think it is ok if represented for that case only?

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John Honovich

(1) is above: that ghosting is solved by IR. Ghosting is solved by making the shutter speed faster (which can be done independent of IR and in the case of this camera would not be slow unless Rayte changed it). Raytec may want to argue that IR makes it brighterbut that's different than ghosting.

(2) is the choice of camera. It's a 4+ year old camera that is not competitive with any recent professional camera. It's misleading that a video published to YouTube in 2014 would feature that camera.

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Undisclosed Manufacturer #2

I'm not familiar with this particular camera, but I did look it up quickly and saw that this can run in a 3MP or a 1.3MP mode. Regardless, this is a 3MP 1/3" imager so it needs more light than, say, a 1.3MP imager. Smaller pixels = less photons per pixel in a given situation.

There are a couple of ways to deal with low light situations. One is to lengthen the shutter time. (I say "lengthen" because some manufacturers call going from, say, 1/10th to 1/30th of a second as "increasing" shutter speed which makes no sense to my frosty head)

The term "shutter speed" is a holdover from optical photography days. Nowadays there really isn't a mechanical shutter uncovering the sensor like we did back in the days of film. Instead, think of each one of those little tiny pixel sensors on your imagers as little bucket for catching light. Each bucket fills up with light during the shutter interval, then dumps it for processing (light level & color) so it can be converted to a number for that pixel on that frame of video.

In low light situations, there might not be enough light in all those little buckets to form a usable image. Again, one way to compensate is to lengthen the time the little buckets can fill up with light. It works great unless whatever you are imaging is moving, because the target's light will smear across many buckets creating what is being called here a ghost effect. (I would call it smearing instead) So lengthening shutter time can only get you so far. Some cameras have fixed shutter speeds, and some others let you choose an adaptive shutter speed -- often with a limit you can set to avoid smearing.

Another way to deal with low light is to use gain. Gain is an amplifier that effectively magnifies the signal coming off the imager. So what would be an unusable image is "boosted" into something usable. AGC stands for "automatic gain circuit" which means you let it add amplification at it sees fit. Gain is measured in decibels but, contrary to ADI's blog, you can't hear it or anything.

The problem with amplifying any signal (audio, video, wireless, anything) is that you also amplify noise. Video noise shows up as grainy little speckles that I call specularity but I'm open to that not being the correct term. The problem with video noise, besides looking crappy, is that all of those speckles are DATA. Darker image, more gain, more noise, higher gain = MORE DATA. This is why, contrary to what you might expect, your bandwidth goes up at night.

So which is better -- lengthening shutter time, or increasing gain? The answer is they are both good up to a point. Too much gain = specularity and higher bandwidth. Too long of a shutter time and you get smearing of moving targets. The trick is to use both as you can, and choose cameras that let you limit each technology.

My guess is this camera was set up for no gain and an automatic shutter speed that is being allowed to go too long which results in smearing. Then, when the illuminator is turned on, the scene has enough light for the shutter time to shorten and eliminate the smearing.

There are other factors that might be in play. Using a faster lens (that lets in more light) and making sure any iris is wide open would help as well. Switching to a lower resolution smaller image format would also help. Fewer pixels = more light per pixel. Finally, making sure this was a true night vision camera that moved the IR cut filter out of the way would be a good idea.

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John Honovich

Thanks for the detailed response. I agree with your general technology observations about pixel size, shutter, F stop, gain, etc.

However, it is very important to emphasize the advances in low light enhancement developed over the past few years. Even with the same f stop, resolution and imager size, today's professional cameras are far better in low light than older ones.

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Alain Bolduc

I say "lengthen" because some manufacturers call going from, say, 1/10th to 1/30th of a second as "increasing" shutter speed which makes no sense to my frosty head

Think of it as as making the shutter go faster. In order for the shutter to open and close 30 (1/30th) times per second, it needs to open and shut fasterat a higher frequency than if it were to open and close 10 (1/10th) times per second.

<edit>Lenghtening exposure time is the opposite of increasing shutter speed, which means you're giving those little buckets more time to fill up, as you say.<edit>

The same thing can be said when moving from a speed of 30 MPH to 50 MPH. The higher the speed, the faster the wheels need to turn.

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Undisclosed Manufacturer #2

"Snowman" was my attempt at a pen name in an environment where my employer forbids me from posting to social media.

While I completely understand my employer's position (look at the trouble some companies get into on this site by their non-PR oriented posters), I still wanted to contribute in a nonpromotional way. I will continue to do so, although a pseudonym may not have been the best idea.

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Undisclosed #3

Even though you can't see your own Undisclosed # in either posts or replies, if you bring up the Discussion list right after you post, it will show the 'latest post' for that particular string - and this shows your Undisclosed #.

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Chris Dearing

I think all the technical points you (and others) made make sense and have solidified my understanding. However, meaning no disrespect, I think I'm missing the full force of the underlying moral outrage and I feel cheated since I like outrage as much as the next guy. ;)

Let me try to frame what I understand you are implying:(please correct)

1. The camera used was never a great low light camera to begin with, and now is positively archaic...

2. Its unlikely that a company like Raytec would not know this camera's performance specs

3. This implies that Raytec either at best carelessly chose the np502 despite its shortcomings or at worst carefully chose it because of its shortcomings, the latter being the more likely...

So I see why you see something fishy there, but let me ask, lets say they wanted to take your criticism to heart and 'clean up their act', couldn't they have used any midrange 2014 camera and then just reduced the ambient light until the slow-shutter slowed enough to start ghosting?

Sure it might have taken a good deal less light, but at some point there's just not enough light right?

So if they had used a 2014 camera and made essentially the same video I'm assuming you would still object just as strenuously.

Therefore the camera mis-step, although easy to point out, would not seem to be theprimary source of your ethical displeasure.

Also, I hear you saying that it is wrong for Raytec to claim that the IR 'solved' the ghosting since they technically only made it brighter to compensate for an unnaturally set slow shutter. But:

Might the camera have been set (as has been suggested) not for an artificially slow-shutter but simply to prefer slow-shutter over high gain?, a common enough choice. Do you feel that this choice is never warranted?

So if the camera was set that way or if they re-do it and do set it that way(using a modern camera), do you still believe that their claim of solving the ghosting problem is underhanded?

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John Honovich

Who asked you to feel 'moral outrage'? This is about spotting mistakes and misleading claims.

Your initial confusion of Raytheon and Raytec is germane. A company like Raytheon may not understand this. A company like Raytec who claims to be the world leading experts on lighting and low light performance most assuredly should know this. Leaving that aside...

If they had used a modern 2013 camera, the results would be far different. The massive ghosting would not happen on any Axis Lightfinder camera, Bosch starlight, Samsung Wisenet III, Sony Gen 6, etc., etc. They literally could not make the same video.

Preferring slow shutter over high gain is not a common technique in video surveillance. Indeed, almost every camera manufacturer defaults to allowing gain to automatically max out in low light but many manufacturers restrict how slow the shutter can get.

Using a slow shutter in a hallway is a very bad idea as obviously people will be walking. Using such a comically slow shutter as they did in this video is even worse.

Raytec decided to use an $800 2009 vintage camera with a $400 add on IR illuminator - a $1,200 solution for a hallway.

Finally, point 3 is that this hallway scenario could have been solved with any number of modern offerings far simpler and less expensive than what Raytec is proposing - such as current low light optimized cameras (mentioned above) or cameras with built in IR (from numerous sources).

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Chris Dearing

No one, my bad, once I 'get the popcorn' I want someone to pay... From now on I will save my outrage for incidents like the Avigicont FOV swapping. Now I am only quietly muttering 'tsk,tsk' while shaking my head...

The massive ghosting would not happen on any Axis Lightfinder camera, Bosch starlight, Samsung Wisenet III, Sony Gen 6, etc., etc. They literally could not make the same video.

Thank you! My error again and this is where I got off-track.

Just out of curiousity, as it pertains to the new cameras, did they eliminate the super-slow shutter speeds or just not allow prioritizing gain vs ss or are just so good that it never helps to have such long exposure times as would cause severe ghosting?

Anyway thanks, lot's of fun, a little outrage, I'm in favor of more test/quizzes they're great for learning!

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John Honovich

Because newer HD professional cameras are so much better in low light than ones from 2009 / 2010, they just do not need to into slow shutter mode (and to the extent they do, it is modest, like 1/15s, not massive like in the Raytec video above). You still can do so if you want and many cameras still default to allowshutter speed to go as low as 1/8s or 1/6sbut it is no longer as needed.

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David Lambert

The video was shot by our Canadian office of an example of the benefits of adding IR. Relevent because I wasn't at the test but I can let you know about it. I can assure you the camera was chosen as one that was "lying around" and not to emphasise a point for our purpose. The scene was in the office, purely as a quick test. The non illuminator video was taken at 16/30 fps to get enough light. With the illuminator the frame rate was set to auto.

Let me arrange a re-test with one of the modern cameras you mention. No problem at all with that. It will still be a 'false' scene because we are trying to demonstrate an effect of adding illumination rather than creating a real world example.

I do think there are 2 kinds of videos, those that are quick insights at the request of our customers and those that are real world examples / scientific tests. This definately falls into the first category but is still very useful in highlighting one of the big advantages of lighting.

Snowman:

You say the choice is between slowing the shutter speed (risking blur / smearing with movement) or increasing the gain (which increases noice and hence badwidth and storage requirements). Actually the best solution is the third way - adding light. Whether that be a stand alone illuminator, integrated bullet camera or general area / white light. Its the best technical solution but obviously more expensive.

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John Honovich

You mention, "The non illuminator video was taken at 16/30 fps to get enough light." Do you mean the shutter speed was set to 16/30s? Was that fixed / locked or was that set as a maximum, meaning the camera could decide whether to go that slow or choose a faster speed?

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David Lambert

As requested, I asked the team to re-do some tests with a modern low light camera. See links below. Remember the original purpose of this exercise was to show that adding light helps you to minimise noise (lots of benefits to bandwidth, storage, image quality, accuracy of analytics etc) and keeps a fast shutter speed (higher frame rates, better quality video, more evidence).

This was a quick practical guide.The camera in these two videos is the Axis Q1602 - one of their lightfinder cameras.

I have to say the tests were done in a dark room so it was very hard work for the camera. It would be interesting to re-do this test in a room where there was "some" ambient light.

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John Honovich

We just released the first ever rating and rankings of IP cameras. The Panasonic NP502 simply failed while the Axis Q1602 was average, getting beat by 12+ cameras. This list might help your people project what cameras most need low light / IR help.

Btw, if I need to monitor a pitch black room, I am still going to use an integrated IR camera over an external IR illuminator... :)

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